Electrochemical and XPS studies of decylamides of α-amino acids adsorption on carbon steel in acidic environment

Synergistic inhibition between o-phenanthroline and chloride ion on cold rolled steel corrosion in phosphoric acid

Understanding the adsorption of 4H-1,2,4-triazole derivatives on mild steel surface in molar hydrochloric acid

The inhibition action of 3,6-bis(2-methoxyphenyl)-1,2-dihydro-1,2,4,5-tetrazine on the corrosion of mild steel in acidic media

Inhibiting effects of some mercapto-triazole derivatives on the corrosion of mild steel in 1.0 M HCl medium

A study was carried out on the inhibition of corrosion and hydrogen embrittlement of AISI 410 stainless steel by two organic inhibitors, namely benzotriazole and benzonitrile. Tensile testing, scanning electron microscopy, weight loss measurements and potentiodynamic polarization were the techniques used for this study. Tensile tests showed that 410 steel is highly susceptible to hydrogen stress cracking. Scanning electron microscopic observations of fracture surfaces showed a brittle quasi-cleavage type of failure when the steel was hydrogen charged from 0.5m H2SO4. Both inhibitors reduced hydrogen induced ductility loss though the fracture mode was unaltered. They showed increasing inhibition efficiencies for corrosion as well as cathodic hydrogen evolution as their concentration in H2SO4 increased from 3.9×10−5m to 8.4×10−3m. Benzonitrile was found to be a more efficient inhibitor than benzotriazole for AISI 410 stainless steel exposed to 0.5m H2SO4.

The inhibition of corrosion and hydrogen embrittlement of AISI 410 stainless steel

The inhibitive action of valeronitrile, benzonitrile and derivatives of benzonitrile on the corrosion and hydrogen embrittlement behaviour of HSLA steel in 0.5m H2SO4 was investigated. All these inhibitors reduced the corrosion rate of the steel with naphthonitrile showing the highest inhibitive efficiency and valeronitrile the lowest. All the inhibitors adsorbed on the steel as per the Temkin adsorption isotherm. The steel become less active on the addition of benzonitrile, 3-chlorobenzonitrile, 4-chlorobenzonitrile, 4-methylbenzonitrile and naphthonitrile to the acid while valeronitrile and 2-chlorobenzonitrile made the steel more active. Naphthonitrile reduced the rate of the hydrogen evolution reaction most efficiently. Derivatives of benzonitrile inhibited hydrogen absorption most effectively.

T. K. G. Namboodhiri

Papers

The inhibition of corrosion and hydrogen embrittlement of AISI 410 stainless steel

Inhibition of corrosion and hydrogen embrittlement of a HSLA steel in 0.5m H2SO4 by nitrile compounds